Cannot Play DVD in WMP/VMCE

[nukmed]

Hello all. My pc freezes completely when I try to play a DVD in both WMP 11 and VMCE. This has never happened before, I get no error message, just a complete lockup - I have to power down via the on/off switch.
I've tried changing the default apps for DVD, but no joy. They play fine with VLC media player, so I'm guessing it's a Windows problem, but I can't find any solution after a long search. I don't want to start uninstalling updates unless I have to!

Many thanks for any suggestions. Vista Ultimate SP1, Dell M2010.

[Baldrick]

Have you installed any codec pack or other video software lately? IF so then uninstall it.

You can also try change default dvd decoder using for example http://mediacenterexpert.blogspot.com/2006/07/vista-media-center-decoder-utility.html

[nukmed]

Hi Baldrick, I've installed no codecs lately - only xvid a year ago. I uninstalled that, but it didn't help. The utility in the link you gave is, according to all my anti-virus stuff, infected with a Trojan - in fact, the website won't even load now. I'm not a regedit expert - scared - but I can't find any MPEG2 Decoder in there.

[Krispy Kritter]

Unless I'm mistaken, Vista doesn't include a mpeg 2 codec by default.